1. Field of the Invention
The present invention relates to an image reading apparatus, and in particular to an image reading apparatus provided with an automatic document conveying apparatus, in which a sheet of a document is separated sheet by sheet from a document of plural sheets and the separated document is conveyed to a reading position, and thereafter an indication of completing the reading operation is printed on the read document.
2. Discussion of the Background Art
Generally, an automatic document feeder (which hereinafter is referred to as an "ADF") is installed in an image reading apparatus such as a copying machine, facsimile device, scanner device, etc. The ADF separates a sheet of a document sheet by sheet from a document having plural sheets, and conveys the separated document sheet to a reading position on a contact glass serving as a document reading stand, and thereafter discharges the document after it is read.
There also exists an image reading apparatus such as a facsimile device or a scanner device which, after finishing the transmission or reading operation, performs a marking at an optional position on the document with a completion stamp, indicating that the document has been read or transmitted.
The completion stamp marking device is installed on the conveying path of the ADF downstream from the reading position. In a case of utilizing the document as a standard position, the marking is performed at a position at a predetermined distance, for instance 10 mm, from the rear end portion of the document in the conveying direction thereof. On the other hand, in a case of setting a reading area, that is, an optional reading area on the document surface, as a standard position, the marking is performed at a position at a predetermined distance, for instance 10 mm, from the rear end portion of the reading area.
However, in such a background art ADF, the position of marking is fixed at either one of the document standard position or the reading area standard position. That is, in the background art the marking indicating completion of reading of the document is preset to be fixed at either a predetermined distance from a rear end of a reading area, or a predetermined distance from a rear end of a document. In the background art only one of these two systems is implemented. For this reason, there arises a problem to be solved that, in the case of adopting the document standard position as the marking position, when a double conveying of plural (two or more) documents improperly occurs, the marking is performed on the next doubly-conveyed document instead of the properly read document.
Furthermore, there arises another problem to be solved that, in the case of adopting the reading area standard position as the marking position, when the length of the manuscript document is shorter than that of the reading area, the marking cannot be performed on the read document. The occurrence of such problems is a defect of the background art.